<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style type="text/css">
        /*txt-aline background-color height vertical-aline line-height
        text-aline background-color height vertical-aline line-height
        text-aline background-color height vertical=aline line-height
        text-aline background-color height vertical-aline line-height
        text-aline background-color height vertical-aline line-height*/
        p{
            text-align: center;
            background-color: lightgreen;
            height: 300px;
            vertical-align: middle;
            line-height: 300px;
        }
    </style>
</head>
<body>
     <p>这是一段有哲理的话</p>
</body>
</html>